Cleavage furrow formation and ingression during animal cytokinesis: a microtubule legacy.

Cytokinesis ensures the proper partitioning of the nuclear and cytoplasmic contents into independent daughter cells at the end of cell division. Although the metazoan mitotic spindle has been implicated in the placement and advancement of the cleavage furrow, the molecules responsible for these processes have remained elusive. Recent studies have provided insights into the role of different microtubule structures and associated proteins in cleavage furrow positioning and ingression together with the signalling events that regulate the dynamics of the equatorial cell cortex during cytokinesis. We try to unify these findings into a general model of cytokinesis in which both astral and central spindle microtubules have the ability to induce furrowing. We further propose that the evolutionarily conserved centralspindlin complex serves as a master controller of cell cleavage in Drosophila by promoting both furrow formation and ingression. The same mechanism might be conserved in other organisms.